If it uses the Crossfire(1) search coils, then any of the CX series search coils will work. You have a variety of search coils to choose from. However, many of them are no longer made and only available used/second hand. For instance, for my Grand Master Hunter metal detectors, which use the Crossfire(1)search coils, I have the 4.5" Super Sniper, the 8.5" Crossfire Supreme Deepseeker as well as the 12.5" Crossfire Supreme Deepseeker. I also have the 3"x7" DD and 5"x10" DD as well as the 10"x14" DD. Finally the 10.5" HotHead which was sold by KellyCo many years ago.
While I don't have or use them, also available are the Rhinotough 7"x10" Elliptical concentric and 9"x12" Elliptical Concentric.
The only ones that I am aware of for purchase brand new from KellyCo are:
1) 4.5" Crossfire Sniper
2) 7"x10" Rhinotough Elliptical Concentric
3) 9"x12" Rhinotough Elliptical Concentric
4) 10"x14" DD PROformance
Here's a link to the KellyCo search coil page:
http://www.kellycodetectors.com/accessories/searchcoils.htm
Look for the CX series search coils under Garrett.
Happy Hunting!